Diabetes mellitus is a major public health problem. In the United States, there are over 10 million patients with diabetes. Diabetes is a syndrome that is caused by a relative or an absolute lack of insulin. Clinically, it is characterized by symptomatic glucose intolerance as well as alterations in lipid and protein metabolism. The maintenance of normal blood sugar levels is achieved by the actions of several hormones, most notably insulin, but also glucagon, epinephrine, corticosteroids, and growth hormone. Hypoglycemia, or low blood sugar, is characterized by below normal levels of blood glucose. On the other hand, hyperglycemia is exemplified by higher than normal concentrations of glucose in the blood. The pancreas produces insulin which is released in response to increased blood glucose concentrations. Insulin works to lower the blood sugar level by stimulating the uptake of glucose by cells. Glucose is used in cellular metabolism to produce energy, or is converted to glycogen for storage in the liver and muscles, or is used in the production of triglycerides and fats.
Water extracts of cinnamon exhibit an insulin potentiating activity, i.e. they increase apparent insulin activity as measured by increased glucose uptake by cells (U.S. Pat. No. 6,200,569). Improved insulin activity leads to decreased circulating insulin, which leads to lower blood glucose and lower glycosylated hemoglobin levels in patients; it also has an effect on smoothing out fluctuations in glucose levels. In the '569 patent, water extracts were prepared by extracting cinnamon plants with water, removing the solid debris, and collecting the liquid extracts. The liquid extracts could be used directly or dried to a powder form.
Mang et al (European J. Clin. Invest. 36:340-344, 2006) report that diabetes mellitus type 2 patients treated with 3 g of cinnamon water extract powder per day for 4 months decreased fasting plasma glucose level, in comparison with placebo-treated patients.
Anderson et al (J. Agric. Food Chem. 52:65-70, 2004) report the isolation and characterization of polyphenol type-A polymers from cinnamon. Two trimers with a molecular mass of 864 and a tetramer with a mass of 1152 were isolated. These polymers are water-soluble and are believed to be the active ingredients of cinnamon that potentiate insulin action and control glucose metabolism.
Cinnamon is composed of between 1-8% of essential oils, in which 65-90% is cinnamaldehyde. (BfR (Bundesinstitut far Risikobewertung) Health Assessment No. 044/2006, Aug. 18, 2006). He et al (J. Agric Food Chem. 53:2424-2428, 2005) found that in 1 g of cassia cinnamon (raw material), cinnamaldehyde level was between 13.1 and 56.9 mg (mean 28.9 mg). Cinnamaldehyde is a yellowish oily liquid and solidifies at −7.5° C. (Merck Index).
Lewis et al. (Environ Health Perspect 104:1011-1016, 1996)) report that cinnamaldehyde was tested positive for potential carcinogenicity in the COMPACT evaluation.
The chemical name of coumarin is 1-benzopyran-2-one (CAS Number: 91-64-5). Coumarin is poorly soluble in water but readily soluble in alcohol. Coumarin is a naturally occurring flavoring substance which is contained in many plants such as woodruff, sweet clover, Tonka beans. Higher concentrations can be found particularly in some types of cinnamon. Large amounts of coumarin can cause hepatic damage—coumarin may only be used as an ingredient of flavorings and other food additives with flavoring properties in the food sector. In animal experiments, coumarin can trigger the formation of tumors. (see BfR Health Assessment No. 043/2006, 16 Jun. 2006) Coumarin is not as potentially toxic as cinnamaldehyde. Still, it is undesirable to have large amounts of coumarin for human consumption.
There exists a need for an improved process to prepare water extract of cinnamon. The improved process reduces the contents of potentially toxic cinnamaldehyde and coumarin in the final product, while maintaining or increasing the active ingredients of cinnamon.